The X Factor judge told Metro: "If I get into something with someone, I've got to be pretty clear from the start that this is serious, otherwise it's just not worth it. It's a lot of pressure on them and me."
She said of fame and relationships: "It can be suffocating. They don't let you have a personal life because they make assumptions about it from the second they find out anything about it.
"It's like they are living a made-up story or their version of your personal life before you actually get to live it. There's your personal life and the personal life they made up for you."
On settling down, she said: "I've got the house. I've moved there now. Halfway there to living the dream."
She explained about her fall-out with Kelly Rowland last year - and loving Nicole Scherzinger this series: "Nicole's found her niche and nailed it.
"She knows what she's doing. It would have been so much more fun if we hated each other.
"I really hit it off with Kelly in the beginning. We tried to get along but then realised we were too feisty. We just weren't getting along."
The singer said that she is "nervous as a solo artist coming out of a band" about her debut album The Female Boss.